Jim McMahon/Mapman®
Knock, knock! Since April, more than 3 million workers have been going door-to-door in India. It’s part of the national census, an official count of everyone living in the country. The census workers are facing a big challenge. India is home to about 1.4 billion people, making it the world’s most populous nation.
Census counters are traveling to every corner of the South Asian country. That includes some of the most crowded cities on Earth. For example, more than 20 million people are packed into each of India’s biggest cities, Mumbai and Delhi. But there are also more than 640,000 villages with much smaller populations spread across India. Some are located on the slopes of snow-covered mountains, while others are in the middle of thick rainforests.